Projector for page printers



July 2, 1946.

R. G. SCHULER- PROJECTOR FOR PAGE PRINTERS Original- Filed Juiy 17, 1940 2 Sheets-Sheet 1 I'll INVENTOR REGINALD -G- SCHULER BY fifi ATTORNEY Patented July 2, 1946 PROJECTOR FOR PAGE PRINTERS Reginald G. Schuler, Highland Park, Ill., assignor to Teletype'Corporation, Chicago, Ill., a corporation of Delaware Original application July 17, 1940, Serial No.

346,003. Divided and this application September 18, 1941, Serial No. 411,373

The present invention pertains to printing telegraph apparatus and more particularly to page printers having movable platens.

This'application is a division of application Serial No. 346,003, filed July 17, 1940.

The primary object of the invention is to provide a page printer having means for automatically distributing the wear of the platen due to the printing impact thereon'.'

Features of the invention reside in providing a disc platen movable with-the type carriage wherein printing is effected on the periphery of the disc and the number of hidden printed characters is reduced to a minimum; and means for assuring even wear of the platen by automatically changing its printing point. haphazardly or in a random manner.

The foregoing and other objects and features of the invention will appear from the following detailed description taken in conjunction with the accompanying drawings, in which.

Fig. 1 is an enlarged side view and partial section of the printer mechanism according to the present invention with part of the optical arrangement with which the printer is associated;

Fig. 2 is an enlarged cross-sectional view of the printer platen and platen frame;

Fig. 3 is a view taken substantially on line 8-8 of Fig. 2; I

Fig. 4 is a top view of the part of the printer mechanism shown in Figs..2 and 3; and

Fig. 5 is an enlarged side view ofa type bar head.

Having reference to Fig. 1 a page printer of the type shown in U. S. Patent 1,904,164 is shown. The printer indicated generally as I6 (and parts of which only have been shown) has been modified in certain respects to adapt it for use with the projector of the present invention. The page printer comprises the side frames 18 and 18 to which is pivoted at 8! a platen frame indicated generally as 82. The usual cylindrical form of platen has been dispensed with in the present embodiment of the invention and has been substituted by the disc form of platen I18 which will be hereinafter described.

To provide a running account of the message printed on the page material a delivery mechanism is provided which comprises a means for permitting the record material to escape from the supply roll, suitable guides, anda webpulling means whereby the page material is advanced through the printing zone. The page material 48 in being withdrawn from'the roll 83 is directed over a slack bar 84 which is pivoted at 85 and is 9 Claims. (Cl. 197-125) normally biased clockwise by a spring 86 to maintain the page material or Cellophane web taut between the roll 83 and a cylindrical guide 81 carried on a shaft 88 journaled in plates 88- depending from side frames 18 and 19. The web 88 is then directed over a roller 9| to which is fixed a ratchet wheel 82, the ratchet wheel and roller being carried on a shaft 88 journaled in the plates 88 secured to side frames18 and 18. Cooperating with the roller 9| is a pressure roller 84 which is carried on a standard .96 secured to a rock shaft 81. Pressure. roller 94 isdrawn into pressing-relation with roller 8| by means of a spring 88. Secured to rock shaft-'91 and located in juxtaposition-to plate 88 is a pressure roller release lever 88. Cooperating with lever 98 is a shoulder IOI on plate 88 arranged so that when lever 89 is actuated counterclockwise against the action of spring 88 it will latch up behind or on the left-hand side 'jof the shoulder IOI thereby releasing the pressure roller 84 from engagement with pressure roller 8| and maintainingthis condition, until lever 98 is again released from the shoulder IOI .to permit spring 88 to bring roller 84 again into pressing relation with roller 8|.

Associated with the ratchet wheel 92 is a pawl i member I02 which is pivoted to a bell crank lever I03 carried on a pivot shaft I04. The depending arm of bell crank lever I03 is pivoted to one end of a'push rod I06, the other end of which is into the path of the function bail blade I08.-

Then, when the push rod I08 is actuated leftwardly by the function bail I08, clockwise rotation is imparted to bell crank lever I03 to impart in turn. downward movement to pawl I02. In this manner, the ratchet wheel 82 is rotated clockwise one step, which through the cooperation of pressure rollers 8| and 94, acts in cooperation with a web pulling device to deliver a'predetermined amount of record material 48 from the supply roll 83 to the printing zone and the projection area.

The record material 48 is brought to the printing position by means of a pulling or drawing mechanism now to be described. The record material 48 as it leaves roller 8| is directed around guide rods I08, III and II2.- These guides rods. may take the form of a fixed rod carrying guide rollers thereon to eliminate friction. From the ,bars MI. 4 :are supported on a movable type carriage, indicated generally by the numeral I42, which is provided with rollers I43 and I 44 whereby it is adaptedto travel on tracks I45 and I46, respectively,

guide rod II2 the record material 49 is directed f vertically through the printing zone and projec- 3 tion field toja guide rod II 3 carried by a Ll-shaped shifting frame member II4 pivotally carried on pivots II5 suitably journaled in the frame indicated generally as I5, which supports'the printer apparatus. The page material 49 is then directed around a guide rod II1 carried in supports II8 wise rotation (as viewed in Fig. l) is imparted to 3 pulley I28 through the instrumentality of a belt I29 connected to a pulley I3I fixed to the main operating shaft I32 of the page printing apparatus shown in Patent 1,904,164. Shaft I32 carries a' "gear (not shown) which meshes with a pinion gear fixed to the shaft of a motor (not shown).

The motor, therefore, imparts continuous rotaftion to pulley I28 which through the friction clutch imparts a constant torque through shaft I24 to spindle I23. With this arrangement the page material 49 is maintained in a taut condi- ,tion between the spindle I23 and the roller 9|. ;Thus, when the ratchet 82 is rotated one step, a predetermined amount of the page material 49 is delivered from the supply roller 83, which ma- This is The code signals control, through a se- (as shown in said patent) a set of curved code Code bars MI and said bell cranks positioned between side frames 18 and 19. Cooperating with code bars I4I are a plurality of pull ibars I41 having individual springs I48. Pull bars ;I41 are operatively connected by rack and pinion connections to a corresponding plurality of type bars I48 pivoted on a shaft I5 I.

Type carriage I42 is also provided with a spacing rack I52 which cooperates with a spacing mechanism (not shown) similar to that illuswith the function bailblade ms.

trated in Patent 1,904,164, to control the movement of type carriage I42 to form character spaces, tending ,in this movement to wind up a carriage return spring mechanism (not shown).

gUpon receipt of the carriage return signal, a funccharacter spacing position of the type carriage I42.- ,Fastened to the printing bail I58 is one end of a printing spring I59, the other end of which 4 is connected to a printing blow adjustment means as shown in Patent 1,904,164. Bail I58 is mounted on a shaft I6I on which is also carried a printing bail actuator I62 which cooperates with a printing cam I63. Actuator I62 carries at the end of its upper arm a stud I64 which has abutting relatioh only with printing bail I 58 and is not permanently connected thereto, which is to permit spring printing. Printing bail I58 is also provided with a pair of arms I66 which carry a function lever bail 4 I69. Also carried on shaft I6I is a function bail comprising arms I65 and I61. Arm I65 is provided with a follower roller which cooperates with a function bail cam I68, and arm I61 supports on its end the function bail, blade I08.

Associated with the selector vanes I38 are a plurality of function levers I01 mounted on pivot rod HI and provided with individual springs I12 which tend to rotate the function levers clockwise into registry with the selector vanes I38. The function levers I01 are normally held out of engagement with the selector vanes I 38 by'means of the rod I69 of the function lever bail.

" As previously mentioned, the platen frame 82 is pivotally supported on pivots 8i in side frames 18 and 19. The platen comprises a circular disc "I13 (Figs. 1, 2, 3, and 4) rotatably mounted on a effective printing edge of the platen I13 being.

located coincident with the printing .point or zone determined by thepath of operation. of the type bar I49.

The platen frame 82 is adapted to berocked from the letters. or unshift position to the "figures or shift position in the manner fully set forth in the afore-mentioned 'Patent 1,904,164. Briefly, the side frame of the platen frame 82 (as shown in Figs. 1 and 2)' is provided. with a lug I11 which operates between two adjustable stops I18 and i 19. Adjacent to lug I11 there is pivoted to the side frame of the. platen frame 82 on pivot I8I, the upper end of a link I82, the 1 lower end of which is pivoted to the horizontal arm of a bell crank lever I83 pivotally mounted at I 84. To-the lower end of the depending arm of bell crank I83 is pivoted a push bar I85, the free end of which overlies a leftwardly directed arm of the function lever I01. Push bar I85 is also provided with a shoulder I86 which cooperates The platen frame 82 and platen I13 are shown in Figs. 1 and 2 in the letters or unshift position, with the stop lug I11 against the upper stop screw I18. This condition is achieved when the function bail blade I08 has operated upon the shoulder I86 to move the pushbar I85 leftwardly to rotate the bell crank I83 clockwise, thus raising the link I82 to cause the platen frame 82 to rock clockwise.

A correspondingly similar construction is provided for the figures" or shift mechanism. That is a shift function lever similar to lever I01 is provided which when selected is caused to rotate clockwise to bring its rearwardly extending arm into operation to raise a push bar, similar to'bar I85, into the path of the function bail blade I08 which, when it is permitted to operate leftwardly (as viewed in Fig. 1) will cause a bell crank lever similar to-bell crank lever I83, to lpllll downga link similar to I82 to rock the platen frame 82 counterclockwise to bring its stop I11 against the lower stop screw I19. Tl? platen frame 82 is maintained in its shift or unshift position by a spring 1 mixed by the forked end of a bar I33, the left end of which (as viewed in Fig. 3) is secured to a member I9I which is secured by screws I32 to the type carriage I42. As viewed in Fig. 4, the circular platen I13 is rotatably mounted on the platen carriage I14 by means ofan eccentric means I93. By means of the adjustment I33 the platen I13 is adjustabletoward and away from the'r'ecord material to vary the clearance therebetween. Rightward and leftward adJustment as viewed in Figs. 9 and 10, is also provided for the platen I13, through the instrumentality of the eccentric adjusting means I93. 1

An important feature of the present invention is the provision of a platen so positioned as to reduce to a minimum the obstruction of the projected image by the platen. To achieve this resultthe platen I13 is tilted with respect to the record material printed upon, sufllciently to clear the light cone. The peripheral surface of the platen I13, upon which printing is effected is slightly beveled so that in one of the shift positions of the platen the peripheral surface of the platen will be parallel to the record material. In

the present embodiment the peripheral surface 'of the platen I 13 is parallel to the record strip when the platen frame 32 has been shifted to the upper case position as indicated in Fig. 2- by the dotted line I94 of the platen I13.

To compensate for this arrangement of the platen I13, the type faces on the type bar I49 are arranged as shown in'Fig. 5. -Moreover, this arrangement'of type faces in cooperation with ashield I38 (Fig. 2) serves (as will. presently alppear) to prevent smudging during the printing.

operation. As is well known, the type bar .149 is 43 provided with an upper case type face I93 anda lower case type face I91 (Fig. 5). However, according to the present invention the lowercase type face I91 is provided with a slope corresponding to the slope of the periphery of the platen I13 when in the lower case position. The dimension 231 of the upper case-type I33 is arranged to be slightly-less lower than the minimum. height 2IIl of the lower case'type I31. When printing is effected in the lower case position, the type face I33 beinglower than the type face I91, will not touch the record material and hence no-smudging of the printed record will occur.

when printing is effected in the upper case position, means is provided for preventing .the lower case type face I31 from comihg into direct. contact with the surface of the record material. To achieve this result a shield I33 is provided which is adapted to be interposed between the type face I31 and the platen I13 when printing is being effected in the upper case position. Shield I93 is secured to the ribbon oscillating member I99, which, as described in the aforementioned Patent 1,904,164 oscillates the inking ribbon into and'out of the path of the type faces during the printing o eration. The ribbon oscillator I39 is pivotally articulated to arm 23I of a lever 232 which in turn is pivoted at 233 to a lever 234 pivoted at 223 to the type carriage which rides on the bottom side of a rail 233 mounted on the platen frame 32, as disclosed in the afore-mentioned Patent 1,904,164. Roller 233 is pressed against the rail 233 by'a spring (not i 5 shown), so that when the platen frame 32' is rocked between the shift and'unshift positions, roller 233 will constantly contact with said rail 233, and lever 232 will be reciprocated therewith.

The depending arm 233 of the lever 232 is operably associated with the pull-bar bail I33 (Fig.

1) so that the reciprocative motion of bail I33 will cause the oscillation of the lever 232 about pivot 233, whether the platen frame 32 is in the shift or the unshift position. Thus when the 15 bail I33 is in its normal position (the leftward positionas shown in Fig. 1)., the lever 232 will hold the inking ribbon, through the instrumentality of the ribbon guide (not shown) located 'at the upper extremity of member I93 (Fig. 2),

in its downward position to eflect visibility of the printed character. Whenthe bail I33 moves rightwardly for a printing operation, the ribbon will be raised to printing position due to the counterclockwise movement imparted to the-lever 232 by the bail I33. When th platen frame 92 is in the position shown in Fig. 2 which is the lower case printing position, the shield I93, upon oscillation of lever 232, will not be raised sufllciently to be interposed between the type face I91 and the platen I13. However, when theplaten frame 32 is in the upper case printing position with the platen. I13 in printing relation with the upper case type face I93, the shield I93 will, upon reciprocation, be raised so as to be- 5 come interposed between the lower case type face I91 and the record material, thus preventing any ink which has accumulated on the type face I31 from smudging the record material.

' As illustrated in Figs. 2, 3, and 4 there is pro- 0 vided a platen rotator for automatically chans- A ing the printing point of the platen I I3 in response to each carriage return operation. As previously described, the platen I13 spaces with the type carriage I42, and accordingly is spaced stepyby-step for character spacing and, upon reaching the end of the line, the platen I13 is returned, rapidly with the carriage I42 to the beginning-of-line position. In contact with the ,5 platen I13 at a point opposite to the printing point is a closely wound coiled spring 233 which, is connected at its ends to the side frame members of the platen supporting frame 32, in such manner that the'platen I13 is caused to rotate as it advances during character spacing. Moreover, upon the rapid return movement of the platen. I13 (under the influence of the carriage return spring-I33) during the performance of the carriage return function, the platen I13 will, owing to the combined sliding and rolling relation with the yieldable spring member 233, rotate haphazardly, thus causing the same printing point of the platen to be presented to the type bars a minimum number of times. In other as words, through the instrumentality of the platen minimum the wear at any given point and hence prolonging the life of the platen. In lieu of the coiled spring 233, a taut wire or cord can, of

course,beused.

It is, of course, manifest that the features I42. Lever 234 is arranged to carry a roller 233 '15 herein disclosed may be modifiedv without departing from the spirit and scope of the pres- What is claimed is:

1-. In a printing apparatus, a printing bail, a plurality of type bars, means for supporting said type bars, said means slidably articulated to said printing bail, a platen cooperably related to said .type bars, means for shifting said platen between two positions indicative oi upper and lower case, means for rendering said platen movable with said type bar supporting means independently of the operation of the platen shifting means, and

means eilective under certain operating condi-' riage, carriage return means, and means efiec-' titve upon each operation of said carriage by said return means to change the rotational position of said platen haphazardly.

3. In a printing apparatus, a printing bail, a

'ent invention, which is intended to be limited I only as set forth in the appended claims.

tive upon each movement of said carriage to: ro-

' tate said platen haphazardly.

able with said type bar supporting means, and

means effective upon each movement of said type bar supporting means to rotate said platen haphazardly.

5. In a printing apparatus, a printing bail, a

I movable type carriage slidably articulated to said printing bail, a platen rotatably'carried by said carriage and movable therewith, and resilient means effective upon each movement o'f-said carriage to rotate said platen.

6. In a printing apparatus, a printing bail, a movable type carriage slidably articulated to said printing bail, a platen rotatably carried by said carriage and movable therewith, and a taut wire means effective upon each movement of said carriage to shift said platen angularly.

7. In a printing apparatus, a printing bail, a movable type carriage slidably articulated to said printing bail, a platen rotatably carried by said carriage and movable therewith, a taut wire instrumentality, and means in said carriage effective in cooperation with said instrumentality upon each movement ofsaid carriage to shift said platen angularly.

8. In a printing apparatus, a printing bail,

movable type carriage slidably articulated to said printing bail, a platen rotatably carried by said carriage and movable therewith, and a coiled spring instrumentality effective upon each movement of said carriage to rotate said platen.

9. In a printing apparatus, a printing bail, a movable type carriage slidably articulated to said printing bail, a platen rotatably carried by said carriage and movable therewith, said platen having a portion of its peripheral surface provided with a circumferential groove, and a coiled spring instrumentality cooperating with said groove, whereby, upon each movement of said carriage, said instrumentality is effective to rotate said platen.

I REGINALD G. SCHULER. 

